Immersion heater



IMMERSION HEATER.

APPLICATION FILED AUG. [7. W21.

J F. McCLOSKEY.

1,438, 1 2 1 Patented Dec. 5, 1922 Patented Dec. 5, 1922.

UNITED STATES PATENT OFFICE.

1 JAMES F. MCCLOSKEY OF WILMINGTON, DELAWARE, ASSIGNOB TO FORD dz MARION,

01? WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

IMMEBSION HEATER.

Application filed August 17, 1921.

To all whom. it may concern:

Be it known that I, J AMES F. MoCLosKEY, a citizen of the United States, residing at \Vilmington, in the county of Nevwcastle b and State of Delaware, have invented a new and useful Immersion Heater, of which the following is a specification. v The present invention is an electrical immersion heater, principally designed for heating liquids when immersed therein.

The main object of the invention is the production of an extremely simple immersion heater whose manufacturing cost is reduced to a minimum, yet having more features of advantage and being more efiicacious than similar known devices. In the type of heater of this invention, it is customary to form the insulating body with a spiral groove in which the resistance coil or wire is disposed in order to maintain it in position, and it is usual for the grooved portion of the body to be enclosed by a protecting casing to keep the coil from contacting or short circuiting. With the present invention the protecting fcasing or shield is unnecessary and eliminated, and the use of a spiral groove, as vi l above mentioned, is found objectionable because convolutions of the heating coil tend to creep, due to expansion and contraction, along the entire length of the groove, thus causing a crowding or bunchinq' effect of the convolutions at the various points along the length of the coil or groove. to shorten the life of the coil because the inevitable corrosion of the coil will cause the convolutions thereof to thicken and bind together where grouped or bunched, thus resulting in minimizing the heat produced.

The construction of the present invention is such that the above stated drawbacks are obviated and the assemblage of the various parts of the heater facilitated as well as lessening the labor and cost in the manufacture of the insulating bodies upon which a the heating coil is mounted. The invention resides particularly in the sundry details of construction, combination and arrangement of parts referred to below and particularly pointed out in the appended claims.

In this specification and the annexed drawings, the invention is disclosed in the formin which it is considered to be the best,

This tends Serial 110. 492,973.

but the invention is not limited to such form because it is capable of being embodied in other forms; and it is to be understood that in and by the claims following the description herein it is intended to cover the invention inwhatever form it mav embody within the scope thereof.

In the drawings which show the preferred embodiment of the. invention" as at present devised, Fig. 1 is a side elevation of the immersion heater showing the particular manner in which the heating coils are wound on the body or insulating portion,

Fig. 2 is a longitudinal sectional view through the heater as shown in Fig. 1, and

Fig. 3 is an under view of the heater shown in Fig. 1.

Referring in detail to the drawings, 1 indicates an elongated insulating body, of porcelain, glass or other suitable material,

preferably in the formof a rod or bar, providing a handle ortio'ii iA having at one end an enlar ement formin the body of the heater. e enlargement l3, preferably, but not necessarily, takes the same cross section as the handle A and is provided throughout its length with a series, preferably three in number, of transverse grooves 2 in the outer surface thereof extending around the circumference of the enlargement at substantially right angles to the longitudinal axis thereof, thus providing the spacing or separating flanges 3. These grooves communicate with each other by means of passages 4 formed in the flanges 3. a

The insulating body 1 base longitudinal tapered bore 5 extending therethrough in which are extended electrical conductors or wires 6 and 7. An aperture 8 extends inwardly at right angles to the longitudinal axis of the heater and "connects the innermost groove 2 with the bore'5. The outer end of the enlargement is formed with a radial slot 9 also for the purpose of connecting the outermost groove 2 with the bore 5.

he heater pro er is contained in the enlargement B an consists of a strand of resistant wire spirally or helically wound and then laid in the grooves 2 as clearly shown in the drawings, with intermediate portions thereof being extendeil through the passages 4 which permit of the winding of the resistance coil as shown. One end of the resistance coil extends through the aperture 8 and is connected at 11 with the conductor 6, while the other end of the coil extends through the slot 9 into the bore 5 and is connected with the other conductor 7 at 12. Thus, it will be observed that current pass ing through one of the conductors, for instance, 6, will traverse the heating coil 10 to the other conductor 7.

The grooves 2 as well as the slot 9 are of greater depth than the diameter of the heating element or coil 10 as clearly shown in the drawings, so that the exposed heating coil can not be brought readily in contact with any object which would cause a short circuit therethrough. It is clear from the drawings that should the heater lie against the side or bottom of a tub, tank or other liquid container, the edges of the flanges 3 project sufliciently beyond the coil to prevent it from engaging therewith. The conductors 6 and 7 are bound together, at a point adjacent their free ends and within the bore 5, with a suitable collar or wrapping 13 which will bind against the tapering walls of the bore 5 to frictlonally hold the conductors in the bore and relieve the heating coil 10 from strain and tension at its points of connection 11' and 12 with the conductors.

In assembling the parts of the heater above described, first the resistance heating coil is placed in the grooves 2 with intermediate portions passing through the passages l, as clearly shown in the drawings. The ends of the conductors 6 and 7 are extended through the upper end Y of the tapered bore 5 through the lower end X thereof. The collar or wrapping 13 is then applied about the end portions of the conductors, as shown 1n the drawings, and the conductors then pulled in the direction of the end Y of the bore to such position that the respective ends of the conductors can be fished and brought through the opening 8 and the slot 9, respectively. Opposite ends of the heating coil 10 are connected to the ends of the conductors 6 and 7, respectively, and the conductors are further pulled through the tapered bore 5 toward the end Y thereof until the collar 13 will frict-ionally bind against the walls of the bore. This last movement of the conductors through the bore moves'the connected ends 11 and 12 of the resistance coil within the bore as clearly shown in the drawings.

The advantage of the present construction is that in winding the coil 10 in the grooves 2 and through passages 4 in .the manner shown, the convolutions of the coil 10 can be properly separated or spacedfrom each other and held under tension in this position in each groove 2, while the ends 11 and 12 of the coil 10 are being connected to the conductors 6 and 7 by reason that the portion of the coil extending through the passages 4. in each flange binding against the walls of the passages, because of its canted position.

An additional advantage is that this particular winding of the coil of the heater eliminates to a large degree the creeping of, the heating coil in the grooves and entirely eliminates. creep of the coil from end to end thereof which would result in bunching together of its convolutions and short-circuit the heating coil at this point, reducing the heat produced; and also with the bunching or crowding of the convolutions obviated, effective surfaces are eliminated against which pressure, from air bubbles formed when heating liquid, may be exerted and which pressure would force portions of the coil 10 sulliciently out of the grooves 2 to touch the sides of the liquid container.

The present construction further permits a more compact wrapping of the same amount of wire over a given area of surface, and in the present instance the heater shown in the drawing can be submerged in 1% inches of water without exposing any of the heating coil to the atmosphere, which eX- posure would cause the same to burn out.

A further and very important advantage of the present construction is that the arrangement of the grooves 2 permits the insulating member 1 to be manufactured at a greatly reduced cost and with less effort and labor than if these grooves were spiral, because of the difficulties which are encoungered in removing the members 1 from the From the foregoing it will be clear that a very simple, economical and practical heater is provided which not only has tea; '3 tures of advantage in its use, but which may. 1

be manufactured at a. very low cost and have its parts assembled with aminimum of effort and manipulation, with all of the parts accurately positioned to obtain the results desired in use, thus placing within the financial reach of all an immersion heater whose utility and advantages are well known.

Having thus described the invention in the formv in which it is at present devised, what is claimed as new and upon which Letters Patent are prayed is:

1. In an electric heating device, a body forming a continuous winding through the grooves and passages, electrical conductors on the body member and having their ends connected with the ends of said helix.

2. In an electric heating device a body member having a series of spaced circumferential grooves therein, said grooves being connected. to each other by passages between the grooves, a helix of electrical resistance material laid in a continuous wind ing in said grooves and passages with the convolutions of the helix spaced apart, said passages forming shoulders at their point of juncture withthe grooves for engaging the helix and preventing slippage or creeping of the latter in each groove, for the purposes set forth.

3. In an electric heating device, an elongated body member of electrical insulating material having a longitudinal bore therethrough, electrical conductors extended through said bore, one end of said body member having a series of spaced circumferential grooves therein, said grooves being connected with each other b passages between the grooves, a helix 0 electrical resistance material laid in a continuous winding in said grooves and passages, the ends of said helix extending through apertures in the body member into said bore of the latter and connected with the ends of said conductors, and means for securing the conductors in position in the bore whereby strain is relieved from the connection of the conductors with said helix.

4. In an electric heating device, an elongated body member of electrical insulating material having a longitudinal bore thereconductors extended one end of the body memt hrough, electrical through said bore,

her having a series of spaced circumferen-' tial grooves on its outer surface, said grooves being connected with each other by passages between the grooves, a helix of electrical resistance material laid in a continuous windin in said grooves and passages, the ends 0. said helix extending through apertures in the body member into said bore of the latter and connected with the ends of said conductors, said grooves and passages being of greater depth than the diameter of said helix for the purposes set forth.

5. In an electric heating device, an elongated bod member of electrical insulating material having a tapering longitudinal bore therethrough, electrical conductors extended through the smaller end of said bore toward the wider end thereof, the end of said body member at the wider end of said' bore having a series of spaced circumferential grooves on 1ts outer surface therein, said grooves being connected with each other by passages between the grooves, a helix of electrical resistance, material laid in a con- 7 tinuous winding in said grooves and passages, the ends of said helix extending conductors in the. bore, and means on said conductors for frictionally engaging the walls of said tapering bore for maintaining the conductors in position therein and to relieve strain from the connections of said conductors with said heating element.

7. In an electric'immersion heater comprising a body member of insulating material having a groove atone end portion and a handle at its outer end portion, a helix of resistance wire disposed in said groove and exposed throughout its length to contact with the liquid in which the heater may be immersed, and means whereby said helix may be connected with a source of electrical ener the said groove being of suflicient dept to protect the helix from contacting with any body with which the sides of the grooved portion of the heater body member may contact, whereby the helix is protected from grounding.

8. In an electric immersion heater comprising a body of insulating material providing a andle member having a groove therein, a. helix of resistance wire disposed in said groove and exposed to contact with the liquid into which the heater may be immersed, means whereby said helix may be connected with a source of electrical energy, said grooved portion of the body being uncovered, said groove being of a depth greater than the diameter of said helix to protect the helix from contacting with any body with which the sides of the grooved portion of the heater body may contact, whereby the helix is pro tected from grounding.

9. In an electric immersion heater comprising a body member of insulating material having a roove therein, a helix of resistance wire disposed in said groove and exposed to contact with the liquid into which the heater may be immersed, means whereby said helix may be connected with a source of electrical energy, the said groove having a bottom wall and side walls extending at an angle to the bottom wall, said side walls being spaced apart approximately the diameter 12 5 of said helix to entirely receive the latter therein and being of a depth greater than the diameter of said helix to provide eaves projecting outwardly for a substantial distance from the outermost surface of the helix the liquid in whieh the heater may be immersed. and means whereb said helix may' he eonneeted with a source of eleetrieal energy. the said grooves and passages being of sultieient depth to proteet the helix from eontaeting with any body with whieh the sides of the grooved portion of the heater hodv member may eontaet. and through which the helix may he grounded.

In testimony whereof I have hereunto set my hand. I

JAMES F. McC-LOSKEY. 

